THE PSEUDO-EVOLUTION OF HALO MASS

By B. Diemer, S. More, Andrey V. Kravtsov. 2012

134 citations recorded by the source corpus.

A dark matter halo is commonly defined as a spherical overdensity of matter with respect to a reference density, such as the critical density or the mean matter density of the universe. Such definitions can lead to a spurious pseudo-evolution of halo mass simply due to redshift evolution of the reference density, even if its physical density profile remains constant over time. We estimate the amount of such pseudo-evolution of mass between z = 1 and 0 for halos identified in a large N-body simulation, and show that it accounts for almost the entire mass evolution of the majority of halos with and can be a significant fraction of the apparent mass growth even for cluster-sized halos. We estimate the magnitude of the pseudo-evolution assuming that halo density profiles remain static in physical coordinates, and show that this simple model predicts the pseudo-evolution of halos identified in numerical simulations to good accuracy, albeit with significant scatter. We discuss the impact of pseudo-evolution on the evolution of the halo mass function and show that the non-evolution of the low-mass end of the halo mass function is the result of a fortuitous cancellation between pseudo-evolution and the absorption of small halos into larger hosts. We also show that the evolution of the low-mass end of the concentration–mass relation observed in simulations is almost entirely due to the pseudo-evolution of mass. Finally, we discuss the implications of our results for the interpretation of the evolution of various scaling relations between the observable properties of galaxies and galaxy clusters and their halo masses.

Subfields: Astronomy and Astrophysics, Electrical and Electronic Engineering, Instrumentation

View Paper: https://www.semanticscholar.org/paper/f7584961b8afa016bff294da13b0032878448a58

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Citations in the corpus

A UNIVERSAL MODEL FOR HALO CONCENTRATIONS (2014, background): “In Diemer et al. (2013b), we demonstrated that the evolution of the c–”
MultiDark simulations: the story of dark matter halo concentrations and density profiles (2014, unknown): “1 (Prada et al. 2006; Cuesta et al. 2008; Diemer et al. 2013).”
DEPENDENCE OF THE OUTER DENSITY PROFILES OF HALOS ON THEIR MASS ACCRETION RATE (2014, background): “During the slow accretion regime, halos mostly pseudo-evolve and their scale radius stays constant (Bullock et al. 2001), but the pseudo-evolution of the virial radius leads to an increase of concentration with time (Diemer et al. 2013b).”
FIRE in the field: Simulating the threshold of galaxy formation (2016, background): “This is because Vmax is a measure of the central gravitational potential and is set relatively early in a halo’s growth history (as opposed to Mvir, which continues to grow even in the absence of physical accretion; Diemer et al. 2013; van den Bosch et al. 2014).”
ON THE LACK OF EVOLUTION IN GALAXY STAR FORMATION EFFICIENCY (2012, background): “…the baryon accretion rate for small halos (Mh < 1012M ) can differ from the dark matter accretion rate through recooling of ejected gas; the changing virial density threshold can also introduce non-physical evolution in the halo mass which affects the accretion rate (Diemer et al. 2012).”
The accretion history of dark matter haloes - III. A physical model for the concentration-mass relation (2015, background): “In this last case, there is a pseudo-evolution in the halo masses (i.e. mass growth due to the definition of the halo in terms of an overdensity criterion; Diemer et al. 2013) and the core radius remains approximately constant, causing the concentrations to grow.”
Forged in FIRE: cusps, cores and baryons in low-mass dwarf galaxies (2015, background): “Below redshift z ∼ 2.5 the inner part of the halo does not show any significant perturbation as there is no significant accretion or merger (Diemand et al. 2007; Diemer et al. 2013).”
THE SPLASHBACK RADIUS AS A PHYSICAL HALO BOUNDARY AND THE GROWTH OF HALO MASS (2015, methodology): “A number of recent studies (Prada et al. 2006; Diemand et al. 2007; Cuesta et al. 2008; Diemer et al. 2013; Diemer & Kravtsov 2014; Zemp 2014; Correa et al. 2015) have pointed out that the inner density profiles of low-mass, galaxy-sized halos evolve very little at z 1 .”
THE SPACE MOTION OF LEO I: THE MASS OF THE MILKY WAY'S DARK MATTER HALO (2012, background): “Since halo virial masses grow with time, due to physical mass accretion or to a time-varying virial overdensity threshold (Diemand et al. 2007b; Diemer et al. 2013), subhalos accreted at early times will be somewhat more tightly bound than those accreted more recently.”
The halo mass function through the cosmic ages (2012, background): “For a recent study on the relative effects of physical and pseudo-mass growth on the SO mass function between z = 0 and 1 see Diemer et al. (2013), and references therein.”
An Accurate Physical Model for Halo Concentrations (2018, background): “…scale radius and central density profile of a halo are assumed to be constant in physical coordinates, and thus that they evolve solely through the growth of their outer boundary RD. Diemer et al. (2013b) demonstrated that this assumption can reproduce the evolution of the low-mass end of the c–”
UniverseMachine: The correlation between galaxy growth and dark matter halo assembly from z = 0−10 (2018, background): “Peak vmax better matches galaxy clustering (Reddick et al. 2013) and avoids pseudo-evolution issues (Diemer et al. 2013).”
EMERGE – an empirical model for the formation of galaxies since z ∼ 10 (2017, unknown): “9 in Diemer et al. 2013).”